As the calendar grinds on into the hottest weeks of summer, the Wisconsin Department of Natural Resources is reminding people to be aware of the dangers of blue-green algae.
Blue-green algae is commonly referred to as “pond scum” and contrary to the name, it can actually be many different colors, including tan, reddish purple or brown. The algae grows most readily in stagnant, nutrient rich water, and can cause illness to both humans and pets if swallowed or contacted with bare skin.
“When environmental conditions are just right, blue-green algae can increase in number,” a report from the DNR said. “Most species are buoyant and will float to the surface, where they form scum layers or floating mats known as a blue-green algae bloom. In Wisconsin, blue-green algae blooms generally occur between mid-June and late September, although in rare instances blooms have been observed in winter, even under the ice.”
The symptoms of blue-green algae poisoning generally include stomach pains, vomiting, diarrhea and/or skin rashes. These occur rarely in humans, and serious side effects occur most often after prolonged exposure to blooms, which generally happens when drinking contaminated water. Worldwide, there has never been a recorded human death related to toxic algae, according to a study by the Utah Department of Health.
Pets are more susceptible to blue-green algae poisoning and the DNR said precautions should be taken if your dogs are regularly exposed to lake water over the summer.
“Do not let pets swim in, or drink waters experiencing blue-green algae blooms or noticeably green water,” the report said. “Keep dogs out of shallow, stagnant water where blue-green algae may be growing on the bottom and dislodged by disturbance. If people shouldn’t swim there, dogs shouldn’t either.”
A regular source of clean, fresh water is always recommended, and the DNR also said to be aware of what the dog brings home on its coat.
“Dogs are particularly susceptible to blue-green algae poisoning because scums can attach to their coats and be swallowed during self-cleaning,” the report said.
Symptoms in pets are similar to those experienced by humans. However, fatalities among dogs and other small animals are rare, and have not definitively occurred in Wisconsin.
The DNR recommends contacting them if you run across what you believe to be a blue-green algae bloom in your area, and the following are some tips for identifying blooms.
Algae blooms will look like there was blue-green paint spilled in the water, and may have surface scum, mats or films. Another sign is if the water is discolored or has green-colored streaks or greenish blobs suspended below the surface.